1. Field of the Invention
The present invention relates to tire traction devices, such as plastic tire chains used to increase the traction of automobile tires in snow or ice.
2. Description of the Prior Art
Tire chains have long been used to increase the traction of vehicles which must be driven in conditions of ice, snow or mud, with the conventional tire chain arrangement being a series of equally spaced cross links connected on their ends by a circular length of chain or webbing. The earlier tire chains which are still utilized today are made of metal, such as steel, and are in the form of a conventional link chain. There are a number of inherent undesirable characteristics in metal tire chains, such as bulkiness, a tendency to rust when stored, difficulty of installation, a tendency to wear out quickly when used on bare pavement, difficulty in repairing broken or damaged cross links, and unpleasant noise levels during use. Additionally, conventional metal tire chains may severely damage the sidewalls of radial tires, which are becoming an increasingly large percentage of the retail passenger car tire market. For these and other reasons, in recent years tire chains have been manufactured of rubber, plastic, or other flexible materials in an attempt to alleviate the aforementioned problems inherent with metal tire chains.
Even though the plastic or rubber tire chains are less subject to damage and breakage than metal tire chains which would necessitiate either replacement of the entire assembly, or of an individual cross link in an assembly, there still is the possibility that a cross member will need to be replaced. The current plastic or rubber tire chain cross links known to the applicants herein are either very difficult to replace, requiring a special repair kit and some degree of mechanical ability, or impossible to replace due to their integral construction. Even if a particular tire chain cross member may be replaceable, in the event that a replacement part is not readily available, there is no provision made for spacing apart the remaining cross members until a replacement is available, due to their fixed character in the total assembly.
One type of prior art plastic tire chain is shown in U.S. Pat. No. 3,817,307, in which transverse strap elements are equally spaced around the circumference of an automobile tire, and are anchored on their ends by a length of steel cable. When the tire skids on soft surfaces such as snow or mud, frictional and mechanical engagement between each strap and the road will cause the strap to automatically deform and twist, thereby bringing a portion of the undersurface of the strap into contact with the snow or mud and assist in stopping the slippage. A number of embodiments are shown in strap element configurations, as well as methods of anchoring to the anchor strap or cable.
U.S. Pat. No. 3,683,990, reveals a tire and a non-skid assembly, with the assembly mounted in transverse grooves provided in the outer circumferential surface of the tire. The assembly will be displaced from the grooves when the tire skids on the road surface and will frictionally engage the road surface and assist in stopping the skid. When the tire returns to normal engagement with the road surface the assembly will automatically return to its normal configuration in the grooves.
U. S. Pat. No. 2,632,491, discloses another plastice or rubber tire chain and comprises a plurality of cross members provided with sintered carbide rivet-like members for extra traction. The cross members are attached together by chain links arranged around each side of the tire.
U. S. Pat. No. 3,092,163, discloses another elastomeric traction device, wherein there are a plurality of cross links interlocked to provide an annular-like shape around the tire. Each cross member has between two and four transverse cross link bands interlocked by peripheral side loops. Each cross member has a tread section consisting of at least two cross bands with a plurality of interconnecting members forming "X" or theta-shaped patterns. Each of the cross links is integrally joined at the ends thereof by elastomeric spring-acting side members, with each cross link having male and female side members which fit the mating side members of the adjacent cross links.
U.S Pat. No. 1,943,918, discloses yet another plastic tire chain configuration wherein the cross straps are of conventional shape and design and connected at their end with permanent or detachable connecting members in the nature of chain links or double folded wire with hooks on each end thereof.
U.S. Pat. No. 1,864,938, illustrates yet another type of flexible tire chain, wherein the cross links are attached to a side chain by means of a double wire hook member, which allows each cross link to be individually removed from the assembly.
While not directly related to vehicle tire traction devices, a number of patents noted in a prior art search disclose various locking devices. U.S. Pat. No. 3,049,778, illustrates a rachet buckle which is used in conjunction with a perforated strap. The buckle has a longitudinal passage therethrough, with a recessed base having a rachet pin thereon. The ratchet pin intersects the passage and has a tapered top surface which acts as a cam surface exposed to one end of the passage. The perforated strap is inserted into the passage at one end of the buckle to a desired distance and the rachet pin inserted through the perforation. The end of the strap is passed out the opposite end of the buckle, a loop is formed and the strap is then reversely threaded through the buckle from the opposite end. The rachet pin is again inserted through the strap to form a means for securing a compact bundle, such as of pipes.
U.S. Pat. No. 1,201,959, illustrates another buckle arrangement wherein a base plate and pin are surrounded by a raised frame with side plates connecting the base and frame. Side loops are provided for the attachment of straps at right angles to the main strap passing through the buckle. The operation of the buckle is much the same as that in the previously described patent.
Another buckle configuration is disclosed in U.S. Pat. No. 812,862, where there are semi-circular members, one of which has an integral crossbar with a pin projecting laterally therefrom. The crossbar is slightly below the plane of the semi-circular members and the free end of the crossbar constitutes a pivot point for mounting in the center of the second semi-circular member. One end of a strap is permanently connected to the crossbar, and upon pivoting the second member on the crossbar a main perforated strap portion may be inserted and the pin inserted through the appropriate perforation in order to form a buckle apparatus for a team of horses hitched together.
U.S. Pat. No. 720,201 illustrates yet another buckle arrangement used to shield harness buckles so that extraneous projections will not be caught in the harness. A short length of shield-strap is secured to the main harness strap with a rivet or stitching, and the free end of the shield-strap is run through a conventional buckle which holds the harness line together.